Sistema de informação para avaliação das afluências de águas interiores à zona costeira do Concelho de Matosinhos

No presente artigo apresenta-se um Sistema de Informação (SI) desenvolvido para caracterizar as águas interiores afluentes ao litoral do concelho de Matosinhos e para suporte ao desenvolvimento de modelos matemáticos que permitam avaliar as áreas de influência e magnitudes das respectivas descargas. O SI foi construído com base em informação existente e em informação complementar obtida através de campanhas pontuais de medição nos locais de descarga. O sistema desenvolvido será utilizado quer na caracterização da qualidade da água quer na construção de modelos matemáticos de simulação da hidrodinâmica e qualidade da água

Effect of high pressure on surfactin production by Bacillus subtilis: implications for its application by the oil industry

Surfactin, a lipopeptide biosurfactant produced by Bacillus subtilis strains, exhibits extraordinary surface active properties, as well as stability at a wide range of temperatures and salinities, making it useful to replace the chemical surfactants in many industrial applications. The oil industry can take advantage of its application to increase the productivity of oil reservoirs, through a technology known as microbial enhanced oil recovery (MEOR). However, in order to make this technology advantageous from an economic point of view, the surfactin-producing strains must be able of growing and producing the biosurfactant inside the oil reservoirs. In this work, B. subtilis #573, isolated from an oil reservoir, was evaluated regarding its ability of producing surfactin under oxygen limited conditions at high pressure. A central composite design (CCD) was used to model the effect of pressure (3.8-46.2 bar) and temperature (35.3-46.7°C) on surfactin production. The results obtained demonstrated that pressure (in the range studied) did not exhibit a negative effect on surfactin production by this isolate, whereas temperatures higher than 45°C reduced its production. For most of the different combinations of pressure and temperature assayed, surfactin production was observed after 24 h, and the surface tension was reduced to values bellow 26.5 mN/m. At 41°C and 47 bar, B. subtilis #573 produced 31 ± 2 mg of surfactin per liter after 24 h, reducing the surface tension to 25.6 ±0.6 mN/m. These results were similar to those achieved at the same temperature at atmospheric pressure (26.0 ± 0.3 mN/m and 27 ± 3 mg surfactin/L). The surfactin produced in both cases exhibited a critical micelle concentration value around 15 mg/L, and the chemical characterization (through UHPLC-MS) demonstrated the production of similar percentages of the different surfactin isoforms (C12-, C13-, C14-, C15- and C16-surfactin) in both conditions. Finally, the applicability of B. subtilis #573 in MEOR was studied in sand-pack columns. In assays performed at 41°C and 47 bar, additional oil recoveries around 14% were obtained after 14 days in in situ assays. These results demonstrate the applicability of B. subtilis #573 in in situ oil recovery processes.info:eu-repo/semantics/publishedVersio

Stereotype movement recognition in children with ASD

The Autism Spectrum Disorders (ASD) covers different events, being one of them body rocking, mouthing, and complex hand and finger movements [1]. The traditional methods for recording the number of occurrences and duration of stereotypes are inadequate and time consuming. Therefore, it was used a commercial system with accelerometers sensors that records the movement of wrist and sends the collected data through a wireless network to the computer. Statistical methods were used to characterize the signal acquired from a previously expressed stereotypy. The parameters that were analyzed are: RMS, Standard Variation, Peaks and Valleys. At the end, the proposed methodology facilitates to identify behavioral patterns special relevant when studying interaction skills in children with ASD

Integração de um servidor web num sistema de pesagem

O presente artigo, descreve a integração das novas tecnologias de informação (TIs) via Web nos sistemas tradicionais de pesagem, dotando estes de grandes facilidades de interligação com outros sistemas ou equipamentos. Destas facilidades podem ser distinguidas as seguintes: leitura dos valores do peso local e remotamente; facilidades de ligação com sistemas de informação, bases de dados e outras formas de gestão e controlo centralizados; fácil ligação dos equipamentos em rede, possibilitando o controlo centralizado dos equipamentos e de todo o material por eles pesado; facilidades de teleassistência e telemanutenção

New trends in biotechnological processes to increase the environmental protection

A sustainable development can be achieved by deepening into more effective and eco-friendly products and technologies. From this point of view, the development of biotechnological processes to increase the environmental protection could be included in the best available techniques reference documents, the so-called BREFs, that cover, as far as practicable, the industrial activities to achieve an integrated pollution prevention and control. Members of the European Union are required to take these documents into account when determining the best available techniques, generally or in specific cases under the European Commission Directives. In order to include biotechnological processes into the BREFs, for example, for obtaining food and pharmaceutical additives, these products have to be cost competitive with those synthesized by chemical ways. Biotechnological processes are advantageous compared to the chemical ones since various metabolites can be obtained simultaneously in the same process, and these metabolites are more eco-friendly than their chemical counterparts. Additionally, this feature also matches the increasing demand of consumers for natural products, which has intensified the biotechnological production of natural additives. This special issue reports advances in the use of biotechnological processes for the treatment of contaminated soil or water as well as the revalorization of agroindustrial residues through the production of valuable metabolites such as biosurfactants or antioxidants, with applications in biomedicine, food industry, pharmaceutical industry, or environmental bioremediation

Esterase production by Aureobasidium pullulans URM 7059 in stirred tank and airlift bioreactors using residual biodiesel glycerol as substrate

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.bej.2021.107954.Aureobasidium pullulans URM 7059 produced esterase using residual glycerol from biodiesel as the sole carbon source. The culture medium containing residual glycerol (0.1% v/v), (NH4)2SO4 (4g/L), and yeast extract (8g/L) resulted in the highest esterase production using shake-flasks. The enzyme exhibited a molar mass of 50kDa and was stable at neutral pH and temperatures below 30°C. The cations Cu2+ and Al3+ did not affect the esterase activity, while Ca2+ promoted the highest activity loss. The enzyme kinetic parameters were determined using different substrates (p-nitrophenylcaprylate and p-nitrophenylbutyrate). Km and Vmax were 1.4mM and 218µmolmin-1 for p-NPC, and 1.55mM and 76.7µmolmin-1 for p-NPB. The esterase production was further evaluated using stirred tank and 2-L airlift bioreactors. The airlift reactor operating at the highest air flow rate (8L/min) increased the enzyme productivity 3-fold compared to the shake-flasks experiments. However, the crude enzymatic extract showed 3 active protein bands by zymography with molecular masses of 172kDa, 66kDa, and 40kDa approximately, suggesting that the pattern of enzyme production changed due to aeration. The crude enzyme degraded the MACO-Sty biopolymer in 14 days, being stable in a wide range of pH (7.0 9.0) and temperatures (40°C 80°C). The results suggest that this enzyme is a promising catalyst in remediation processes.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004), projects MultiBiorefinery (POCI-01-0145-FEDER016403) and Lignozymes (POCI-01-0145-FEDER-029773), all funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. In Brazil, this study was financed in part by the Coordenaçao ˜ de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors also thank the CNPq and FUNCAP for financial support.info:eu-repo/semantics/publishedVersio

Technical and economical evaluation of modular multilevel converters for the electrical power grid interface

Over the past few years, it has been verified a raise in the demand, as well as the price of electricity, urging the need for the development of more efficient power converting systems. Two of the most used power converters are the AC-DC, commonly known as rectifier, and the DC-AC, commonly known as power inverter. There are many different topologies for both the referred converters, but one of the most common is the H-Bridge, which can operate as a bidirectional converter that enables the possibility of a single power converter working either as an active rectifier or a grid-tied power inverter, according to the application in use. In this paper, a Modular Multilevel Converter topology is presented and compared to the most conventional bidirectional power converter, discussing both technical and economical details recurring to simulations and a critic analysis of the results, which allows the understanding of the tied relation between economics and engineering, optimizing the functionality of the converter, as well as the costs associated with R&D and production in short term, and the efficiency in the long term.This work has been supported by FCT -Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the MEGASOLAR Project POCI-01-0247-FEDER-047220

Improved rhamnolipid biosurfactant production by Burkholderia thailandensis E264 using agro-industrial wastes

Biosurfactants are amphiphilic surface-active compounds, produced by various microorganisms, that reduce surface and interfacial tension. These compounds are attracting increasing interest over their chemical counterparts due to their advantages, such as biodegradability, high stability in extreme environments, low toxicity, low critical micelle concentrations (CMC) and the fact that they can be effectively produced from agro-industrial wastes and renewable resources. Furthermore, their diversity allows for a significant number of uses, including microbial enhanced oil recovery (MEOR), bioremediation and biomedical applications. However, the high operational costs, mainly regarding the use of expensive raw materials in the fermentation and the complex downstream processing due to the low production yields restricts their industrial-scale applications. Several attempts to solve these limitations by reducing the production costs have been conducted and include the use of low-cost agro-industrial wastes and by-products as substrates. One of these low-cost substrates, that has been successfully used to produce biosurfactants by Bacillus subtilis and Pseudomonas aeruginosa, is corn steep liquor (CSL). In this work, CSL is evaluated for rhamnolipid biosurfactant production by Burkholderia thailandensis E264. When grown in a culture medium containing CSL (7.5% v/v) as sole substrate, this strain produced 1.8 g rhamnolipid/L, which is about 2.6 times the amount of rhamnolipid produced in the standard synthetic medium. By supplementing the culture medium with olive oil mill wastewater (OMW, 10% v/v), a residue originating from the olive oil extraction industry, rhamnolipid production was increased up to 2.6 g/L, most likely due to the inductive effect of long-chain fatty acids present in OMW (mainly oleic, palmitic, linoleic and stearic acids) on rhamnolipid production. Rhamnolipids purification was also done and the biosurfactant produced in the low-cost medium (CSL + OMW) exhibited better surface-active properties when compared with those produced in the synthetic medium, reducing the surface tension of water to 26.8 ± 0.1 mN/m, with a CMC of 280 mg/L (28.8 ± 0.2 mN/m and 460 mg/L, respectively, in the synthetic medium). These results demonstrate that rhamnolipid production is more efficient in the low-cost medium. Furthermore, to the best of the authors knowledge, this is the first experimental research that describes the utilization of CSL and CSL + OMW as substrates for the production of rhamnolipids by B. thailandensis, with very optimistic results in terms of cost and production levels.This work was sponsored by PARTEX Oil and Gas and it was supported by the Portuguese Foundation for Science and Technology(FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Development and experimental validation of a reduced-scale single-phase modular multilevel converter applied to a railway static converter

With special emphasis in recent years, an increase has been verified not only in demand but also in the price of electricity, arising the need to develop more reliable and efficient electrical energy conversion systems. In this context, emerges the utilization of the modular multilevel converter (MMC) based on submodules. The key to the MMC is modularity, which allows the converter to reach higher performance levels, improving the voltage and current output signals of the converter, in a compact solution. The modularity concept allows the increase of the operation voltage using submodules in series, and the increase of the operating current using submodules in parallel. Additionally, in the event of a submodule malfunction, the converter can be reconfigured and continue the operation, albeit at a lower power level. Due to its versatility, the MMC can be used in a variety of applications, such as HVDC power transmission systems, solid-state transformers, renewable energy interfaces, and more recently, railway power systems. In this context, this paper focuses on the development and experimental validation of a single-phase MMC based on the use of half-bridge submodules applied to a railway static converter, where the main focus lies on the AC side control. The control algorithms are fully described for a single-phase MMC reduced-scale prototype implemented (500 W, 230 V–50 Hz, 200 VDC), connecting two submodules in series in the upper arm, two submodules also in series in the lower arm, the respective driver and command circuits, sensing and signal conditioning circuits, as well as a digital control platform recurring to the DSP TMS320F28379D. Experimental results were obtained to validate each submodule individually, and, later, to verify the operation of the MMC with the set of four submodules.This work has been supported by FCT–Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the MEGASOLAR Project POCI-01-0247-FEDER-047220